340 CEUSTACEA. 



sides little arcuate, antero-lateral margin one-em argin ate. Third 

 joint of outer maxillipeds hardly longer than broad. Epistome 

 short, acutely cristate either side. Anterior feet rather small, hand 

 and carpus above sparsely granulous, hand externally very nearly 

 smooth, towards lower side faint costate. Posterior feet naked; 

 tarsus long, dorsal spines much shorter than those below. 



Plate 21, fig. 4 a, male, natural size ; b, under view, four diameters; 

 c, hand, natural size ; d, outline of arm. 



Paumotu Archipelago. 



Length of carapax, nine and a half lines ; breadth, ten and three- 

 fourths lines; length of front, five lines, and breadth (to prsemedials), 

 hardly a line. The third joint of the outer maxillipeds is short, as in 

 the planifrorts; but the front is abrupt and very narrow, and there is 

 but one emargination in the antero-lateral margin. The tarsus is 

 quite long, and has a neater or more naked aspect than usual, from 

 the shortness of the dorsal spinules ; and there is a densely ciliate line 

 near dorsal margin. 



The third joint of the last pair of legs is three or four-denticulate 

 at the inferior apex. The postero-lateral surface of carapax is 

 strongly lined transversely. 



G. lonyitarsis, Dana, Proc. Acad. Nat. Sci. Philad., 1851, v. 249. 



Geapsus lividus, Edwards. 



Plate 21, fig. 5 a, male, natural size ; b, outer maxillipeds, enlarged 

 two diameters ; c, hand, natural size. 



Island of San Lorenzo, Peru. 



Length of carapax, eleven lines; breadth, thirteen and a half lines; 

 length of front, five and a half lines, and breadth (to prsemedials) , about 

 one line. Colour, mostly dark chestnut-brown, in transverse linings. 

 The carapax is naked and smoothish, nearly square, the sides being 

 sparingly arcuate anteriorly, front abrupt. Anterior feet nearly 



